Funnily enough it is my current car a 2006 Toyota Yaris T3. I have been driving for over 50 years and I have owned all sorts of cars from Austin Healey to VW Combi with a Subaru and Daimler Sovereign thrown in for good measure.
I have always had lower back problems and could never drive any car for more than an hour without getting extreme back pain and sciatica in my legs. I don't know what Toyota have done to the seat in the Yaris but I can drive it all day without any pain. This is my first Toyota and I will never have a different make again.
Current car. 2011 Polo 1.6. Naturally aspirated goodness. Not the fastest but beats some 1.0 turbos on economy. Can get it as low as 4.6L/100km on the drive between JHB and PTA with mild traffic. Will never sell this car.
My 1997 Mondeo 2.0 Aspen was an awesome car. Good handling, performance, and fuel consumption, and it was the most reliable car I've ever owned, by a long way. I traded it in for a 2002 Mondeo 2.0 Ghia, which had more features (and the best seats and climate control I've had in any car), but ate clutches a lot in my heavy traffic. My current car, a Merc C180K Estate, is one of those cars that has some minor niggles, but has given me a sense of trust. And it's an auto, of course.